CMake 4.2.0-rc2 is ready for testing
October 31, 2025
I am proud to announce the second CMake 4.2 release candidate.
https://cmake.org/download/
Documentation is available at:
https://cmake.org/cmake/help/v4.2
Release notes appear below and are also published at
https://cmake.org/cmake/help/v4.2/release/4.2.html
Release milestone is available at:
release milestone
Some of the most significant changes in CMake 4.2 are:
-
The “Visual Studio 18 2026” generator was added. This is
experimental and based on “Visual Studio 2026 Insiders” because this
version of VS has not been released. -
The “FASTBuild” generator was added.
-
CMake now supports Cross Compiling for Emscripten with simple
toolchain files. -
The “set(CACHE{<variable>})” and “unset(CACHE{<variable>})” commands
were added to explicitly set and unset cache entries. -
The “INSTALL_OBJECT_NAME” source file property was added to control
names of installed object files for specific compiled sources. -
Nearly all find modules now provide a “<PackageName>_VERSION” result
variable matching the casing of its module name. Existing variants
such as “<PackageName>_VERSION_STRING” and uppercased
“<PACKAGENAME>_VERSION” are deprecated. See documentation of each
find module for details. -
The “ExternalProject” module’s “ExternalProject_Add()” and
“ExternalProject_Add_Step()” commands now provide options to set
environment variables on the configure, build, install, and test
steps. -
The “Visual Studio 14 2015” generator is now deprecated and will be
removed in a future version of CMake.
CMake 4.2 Release Notes
***********************
Changes made since CMake 4.1 include the following.
New Features
============
File-Based API
--------------
* The "cmake-file-api(7)" "codemodel" version 2 "version" field has
been updated to 2.9.
* The "cmake-file-api(7)" "codemodel" version 2 "target" and
"directory" objects gained a new "codemodelVersion" field.
* The "cmake-file-api(7)" "codemodel" version 2 now includes imported
targets and all interface library targets in its replies.
Previously, imported targets were omitted, and only those interface
targets that participated in the build system were included. The
following changes support these new additions:
* The "target" object gained "imported", "local", and "abstract"
fields.
* The "target" object's "type" field can now also hold the value
"UNKNOWN_LIBRARY".
* The "codemodel" object's "configurations" entries gained a new
"abstractTargets" array.
* Entries in the "directories" and "projects" arrays of the
"codemodel" object's "configurations" entries gained a new
"abstractTargetIndexes" array.
* The "cmake-file-api(7)" "codemodel" version 2 "target" object gained
new "linkLibraries", "interfaceLinkLibraries",
"compileDependencies", "interfaceCompileDependencies",
"objectDependencies", and "orderDependencies" fields.
Generators
----------
* The "Visual Studio 18 2026" generator was added. This is
experimental and based on "Visual Studio 2026 Insiders" because this
version of VS has not been released.
* The "FASTBuild" generator was added.
Platforms
---------
* CMake now supports Cross Compiling for Emscripten with simple
toolchain files.
Command-Line
------------
* The "cmake(1)" command-line tool now supports "cmake -E
copy_if_newer" and "cmake -E copy_directory_if_newer" subcommands to
copy files based on timestamp comparison instead of content
comparison. These commands copy files only if the source is newer
than the destination, providing better performance for build systems
compared to "copy_if_different" which compares file contents.
Commands
--------
* The "cmake_language(TRACE)" command was added to enable or disable
tracing during script execution.
* The "set(CACHE{<variable>})" and "unset(CACHE{<variable>})" commands
were added to explicitly set and unset cache entries.
* The "string(REGEX QUOTE)" command was added to generate a regular
expression exactly matching a string.
Variables
---------
* The "CMAKE_CXX_STDLIB_MODULES_JSON" variable was added to set the
path to the "import std" metadata file for the standard library
rather than using the compiler to discover its location.
* The "CMAKE_INTERMEDIATE_DIR_STRATEGY" variable and corresponding
"CMAKE_INTERMEDIATE_DIR_STRATEGY" environment variable were added to
change the strategy used to name intermediate directories used for
object files and other associated target metadata.
* The "CMAKE_AUTOGEN_INTERMEDIATE_DIR_STRATEGY" variable and
corresponding "CMAKE_AUTOGEN_INTERMEDIATE_DIR_STRATEGY" environment
variable were added to change the strategy used to name intermediate
directories used for "Qt Autogen" files.
* The "CMAKE_SKIP_LINTING" variable and corresponding "SKIP_LINTING"
target property were added to tell the Command-Line Build Tool
Generators to skip linting all sources in a target.
Properties
----------
* The "INSTALL_OBJECT_NAME" source file property was added to control
names of installed object files for specific compiled sources.
* The "INSTALL_OBJECT_NAME_STRATEGY" target property was added to
control the naming strategy for installed object files.
* The "INSTALL_OBJECT_ONLY_USE_DESTINATION" target property was added
to more precisely control the installation path for object files.
* The "JOB_POOL_COMPILE" source file property was added to assign
individual source compilations to "JOB_POOLS".
* The "OBJECT_NAME" source file property was added to control object
names of compiled source files.
* The "UNITY_BUILD_FILENAME_PREFIX" target property was added to
control names of source files generated by "UNITY_BUILD".
Modules
-------
* Nearly all find modules now provide a "<PackageName>_VERSION" result
variable matching the casing of its module name. Existing variants
such as "<PackageName>_VERSION_STRING" and uppercased
"<PACKAGENAME>_VERSION" are deprecated. See documentation of each
find module for details.
* The "CheckTypeSize" module's "check_type_size()" command gained a
new "RESULT_VARIABLE" keyword to customize the result variable name
instead of the default "HAVE_<size-var>".
* The "ExternalProject" module's "ExternalProject_Add()" and
"ExternalProject_Add_Step()" commands now provide options to set
environment variables on the configure, build, install, and test
steps.
* The "FindPython3", "FindPython2", and "FindPython" modules no longer
make "NumPy" depend on "Development.Module". See policy "CMP0201".
* The "GoogleTest" module's "gtest_discover_tests()" command now sets
the "DEF_SOURCE_LINE" test property for each discovered test if
gtest supports the "--gtest_output=json" option. This test property
is used by some IDEs to locate the source for each test.
* The "UseSWIG" module's "swig_add_library()" command gained a
"DEBUG_POSTFIX" option to control the "DEBUG_POSTFIX" target
property.
Generator Expressions
---------------------
* The "<LANG>_COMPILER_LINKER_ID" and
"<LANG>_COMPILER_LINKER_FRONTEND_VARIANT" families of generator
expressions were added to access the value of the associated
"CMAKE_<LANG>_COMPILER_LINKER_ID" and
"CMAKE_<LANG>_COMPILER_LINKER_FRONTEND_VARIANT" variables.
* The "TARGET_FILE_BASE_NAME", "TARGET_IMPORT_FILE_BASE_NAME",
"TARGET_LINKER_FILE_BASE_NAME",
"TARGET_LINKER_LIBRARY_FILE_BASE_NAME",
"TARGET_LINKER_IMPORT_FILE_BASE_NAME", and
"TARGET_PDB_FILE_BASE_NAME" generator expressions gained a "POSTFIX"
option to control the inclusion of the "<CONFIG>_POSTFIX" target
property as part of the base names of the corresponding files.
* The "TARGET_INTERMEDIATE_DIR" generator expression was added to
refer to a target's intermediate files directory in the build tree.
CPack
-----
* The "CPACK_PACKAGE_CHECKSUM" variable now supports multiple values.
* The "CPack NSIS Generator" gained a "CPACK_NSIS_CRC_CHECK" variable
for setting the "CRCCheck" attribute.
* The "CPack WIX Generator" gained a "CPACK_WIX_CAB_PER_COMPONENT"
variable to enable one ".cab" per component.
Deprecated and Removed Features
===============================
* All find modules now provide a "<PackageName>_FOUND" result variable
matching the casing of its module name. Existing variants, such as
the uppercased "<PACKAGENAME>_FOUND", are deprecated where
appropriate. See documentation of each find module for details.
* The "FindwxWidgets" module's result variable "wxWidgets_USE_FILE" is
now deprecated in favor of including the "UsewxWidgets" module
directly.
* The "Visual Studio 14 2015" generator is now deprecated and will be
removed in a future version of CMake.
Other Changes
=============
* The "$<CONFIG:cfgs>" generator expression, when appearing on an
imported target, has been fixed to only match the configuration
actually being consumed. See policy "CMP0199".
* Selection of configuration and location of imported targets is now
more consistent. See policy "CMP0200".
* The "CMAKE_PARENT_LIST_FILE" variable is no longer defined when
processing a "CMakeLists.txt" file. See policy "CMP0198".
* For builds targeting the MSVC ABI, all generators now add the
"_MBCS" preprocessor definition when compiling sources unless
"_UNICODE" or "_SBCS" is found. See policy "CMP0204".
* For builds targeting the MSVC ABI, all generators now add the
"_WINDLL" preprocessor definition when compiling sources in shared
libraries. See policy "CMP0203".
----------------------------------------------------------------------------
Changes made since CMake 4.2.0-rc1:
AJIOB (4):
Tests/RunCMake: Match xxx.cmake file name more precisely
Tests/RunCMake: Match CMakeLists.txt file name more precisely
Tests/RunCMake: fix version typo
Tests/RunCMake: Match dots more precisely, part 3
Andrej730 (3):
UseSWIG: Issue `swig_link_libraries` deprecation warning if CMP0078 is NEW
Tests: Fix RunCMake.UseSWIG SetPOSTFIX case on Windows
FindPython: Support getting DEBUG_POSTFIX without requiring Interpreter
Ben Boeckel (4):
PrecompileHeaders: downgrade `REUSE_FROM` without a PCH to a warning
Help/OPTIMIZE_DEPENDENCIES: fix parity of which files are considered
HELP/OPTIMIZE_DEPENDENCIES: fix reST markup
VS: do not create `ProgramDataBaseFileName` entries without a filepath
Brad King (18):
Compilers: Use -print-sysroot output only with successful exit code
Tests: Remove outdated CMake.PolicyCheck test
Help: Clarify 4.2 release note on `$<CONFIG>` policy CMP0199
ci: add unzip to cuda13.0 base image
macOS: Remove outdated condition for CMAKE_OSX_DEPLOYMENT_TARGET
macOS: Avoid relying on sw_vers when cross-compiling from another OS
VS: Fix SLNX generation so CSharp projects build in the IDE
Tests/FindBoost/TestPython: Improve python version list formatting
ci: Add job for CUDA with FASTBuild generator on Linux
ci: Add script to repackage macOS SDKs
ci: Add script to install macOS SDK version 15.5
ci: Revert packaging to macOS 15.5 SDK to restore cmake-gui rendering
Apple: Initialize deployment target after SDK
Xcode: Restore default CMAKE_OSX_DEPLOYMENT_TARGET to run on host
Tutorial: Restore source archive when published on cmake.org
VS: Restore support for Intel Fortran projects
macOS: Do not incorrectly search for per-arch SDKs
CMake 4.2.0-rc2
Craig Scott (1):
GoogleTest: Avoid POST_BUILD race condition for gtest_discover_tests()
Eduard Voronkin (6):
FASTbuild: allow setting custom IDE args
FASTBuild: Explicitly disallow CUDA language since it is not implemented
FASTBuild: optimize try_compile builds
FASTBuild: support CUDA language
FASTBuild: Disable caching and distribution in try_compile builds
FASTBuild: generate compile_commands
Karolina Surma (1):
FindPython: Add support for Python 3.15
Marc Chevrier (1):
Makefiles: Position target-wide link flags consistently with other generators
Martin Duffy (3):
install(PACKAGE_INFO): Fix error when usage requirements contain certain genex
instrumentation: Only quote arguments that contain a space
instrumentation: Add showOnly to ctest snippets
Matthew Woehlke (5):
Help: Add missing gate for project(SPDX_LICENSE)
find_package: Respect CPS license
Help: Improve documentation of project SPDX_LICENSE
cmPackageInfoArguments: Improve error message
CPS: Improve invalid namespace error
Ottmar Zittlau (1):
GoogleTest: Restore support for empty discovered test list
Tristan Daifuku (1):
Linker: Tolerate CMAKE_EXECUTE_PROCESS_COMMAND_ERROR_IS_FATAL set to ANY
Tyler Yankee (3):
Tests/Instrumentation: Remove unused files
Help/instrumentation: Fix link to CMake Content File
instrumentation: Fix snippet `result` field
Vito Gamberini (2):
Tutorial: Update IPO example in Step 6
Tutorial: Add Step 0 to prepare the working environment